Oral Presentations - Pathology and Laboratory Medicine - University ...

ResidentAbstract # 8Vincent Fung 1 , Jenny Baybik2, Kim Chi 31Department of Pathology and Laboratory Medicine, University of British ColumbiaaVincent Fungevaluation of circulating tumor cells as prognosticmarkers in patients with metastatic renal cellcarcinoma (mRCC) receiving systemic therapyBackround/ObjectivesRecently, the enumeration of circulating tumor cells (CTC) in peripheral blood has been evaluated as a prognosticmarker for various cancers including breast, prostate and colorectal. The presence of >4-5 CTC in 7.5 ml of peripheralblood before and/or after initiation of a new line of therapy is one of the strongest prognostic indicators of overallsurvival in these cancers. The Veridex CellSearch system is the only FDA approved commercially available assay. Itis highly reproducible, specific and sensitive. As an adjunct to current standard testing methods, this assay has beenused clinically to provide a more complete picture of patient prognosis. Our goal is to evaluate the potential utility ofenumerating CTC in patients with mRCC.MethodsInitially, patients in Canada with mRCC enrolled onto a phase III trial of second-line therapy of temsirolimus vs.sorafenib were evaluated for CTC. Blood was drawn at baseline, after cycle 2, and at time of treatment failure.Samples were processed on the CellTracks AutoPrep System® with the CellSearch Circulating Tumor Cell Kit®.Epithelial cells in the enriched sample were characterized and counted (CK+/DAPI+/CD45-) with the CellTracksAnalyzer II®.ResultsSamples from 12 patients were collected with a range of 0-38 CTC/7.5 ml of blood at baseline. Five of 12 patients(42%) had CTC counts of ≥5. Nine of these patients had CTC counts performed after cycle 2: 4/9 (44%) had CTCcounts ≥ 5 with 1 patient having a decrease in CTC counts from ≥5 to